Soot from Arctic Wildfires Hover Over Greenland

Recent observations from satellites have shown that the smoke from Arctic wildfires is drifting over the Greenland ice sheet, settling on the ice as soot and making it more likely to melt under the sun.

Dec 05, 2012

At the American Geophysical Union, an Ohio State University researcher presented images from NASA’s Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite, which captured smoke from Arctic fires billowing out over Greenland during the summer of 2012.

Jason Box, associate professor of geography at Ohio State, said that researchers are concerned with how the Greenland landscape is losing its reflective quality as temperatures continue to rise. The surface is darkening as ice melts away, and, since dark surfaces are less reflective than light ones, the surface captures more heat and leads to stronger and more prolonged melting.

Along with the already melting conditions in Greenland, researchers believe that soot from wildfires is a second environmental effect that is darkening polar ices, and may be becoming more common in the Arctic.

“Soot is an extremely powerful light absorber,” Box said. “It settles over the ice and captures the sun’s heat. That’s why increasing tundra wildfires have the potential to accelerate the melting in Greenland.”

In the Arctic, rising temperatures may be causing tundra wildfires to become more common. To find evidence of soot deposition from these fires, Box and his team first used thermal images from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) to identify large fires in the region. The researchers then used computer models to project possible smoke particle trajectories, which suggested that the smoke from various fires could indeed reach Greenland.

In order to truly measure the extent to which soot particles enhance melting is to take ice sheet surface samples, Box is organizing a Greenland ice sheet expedition for 2013. The Dark Snow Project expedition is to be the first of its kind, made possible by crowd-source funding.